CODEWITHSUNDEEP
bashshellloggingtimestamp
daylightsaving
daylightsaving

Reputation: 35

Timestamp variable in my Bash Shell Script is not changing in log file

I have a shell script that calls 2 other scripts that take many positional parameters.

Main Script

LOGFILE="status.log"
TIMESTAMP="`date "+%Y-%m-%d %H:%M:%S"` $BASH_SOURCE : "

sudo ./call_script_A arg1 arg2 
echo "$TIMESTAMP task 1 complete" | tee -a $LOGFILE

sudo ./call_script_B arg1 arg2 arg3 
echo "$TIMESTAMP task 2 complete" | tee -a $LOGFILE

.
.
.
sudo ./call_script_A arg1 arg2 arg3 arg4
echo "$TIMESTAMP task n complete" | tee -a $LOGFILE

And the output log from the above script after several hours was:

2020-08-28 09:44:43 ./main_script.sh : task 1 complete 
2020-08-28 09:44:43 ./main_script.sh : task 2 complete 
2020-08-28 09:44:43 ./main_script.sh : task 3 complete 
2020-08-28 09:44:43 ./main_script.sh : task 4 complete 
2020-08-28 09:44:43 ./main_script.sh : task 5 complete 
2020-08-28 09:44:43 ./main_script.sh : task n complete

Notice how the timestamps stay constant despite the fact that its been echo'd several times in the main script above?

On all my scripts, i have the below 2 lines.

LOGFILE="status.log"
TIMESTAMP="`date "+%Y-%m-%d %H:%M:%S"` $BASH_SOURCE : "

How do I debug this situation considering the fact that I am using these variables across all my scripts?

Upvotes: 0

Views: 1036

Answers (1)

Paul Hodges
Paul Hodges

Reputation: 15293

The subshell evaluates before assigning the variable. What you want is a function.

$: logfile="status.log"

$: Log() {
    echo "$(date '+%Y-%m-%d %H:%M:%S') $BASH_SOURCE : $@" | tee -a $logfile
   }

$: Log task     1        complete 
2020-08-28 13:44:58 main : task 1 complete

$: cat status.log
2020-08-28 13:44:58 main : task 1 complete

$:     Log "task 2 complete"
2020-08-28 13:45:26 main : task 2 complete

$: cat status.log
2020-08-28 13:44:58 main : task 1 complete
2020-08-28 13:45:26 main : task 2 complete

$:     Log "task      3       complete"
2020-08-28 13:49:28 main : task      3       complete

$: cat status.log
2020-08-28 13:44:58 main : task 1 complete
2020-08-28 13:45:26 main : task 2 complete
2020-08-28 13:49:28 main : task      3       complete

Upvotes: 2

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